A culture microscope is an example of a device for observing conditions while living cells are being cultured. A culture microscope is provided with a culturing device (incubator) for forming an environment suitable for culturing cells, and a microscope viewing system for performing microscope viewing of the state of cells inside a culture container accommodated in the culturing device. The culture microscope is configured so as to obtain an image of an observed cell at respective predetermined times that have been set in advance, reproduce the obtained images as a continuous projection using, e.g., time-lapse imaging or another technique, and visually ascertain in a simple manner the state of activity of the cells (e.g., see Patent Document 1).
In such a device, foreign matter (non-objects) such as dirt, bubbles, dead cells, and the like may be found together with living cells, which are the observation object in the culture container. Accordingly, a method for distinguishing between observation objects and non-objects when cells are tracked has involved detecting the presence of cell nuclei, cell matter, and the like; and determining whether or not they are living cells.
Patent Document 1: Japanese Laid-open Patent Publication No. 2004-229619